The mission of Bioniks is to develop and commercialize accurate, low-cost movement analysis systems for clinicians, ergonomists, athletic trainers, and other professionals interested in quantifying human movement. Our initial focus is on developing computer enhancements for inexpensive 3D cameras like the Microsoft Kinect. These enhancements surpass the accuracy limitations of state-of-the-art skeleton by combining established marker-based measurement protocols and advanced computer vision techniques, to generate clinical-quality 3D human motion data. Difficult to obtain outside a laboratory setting, these kinematic data are inherently valuable for several NIH priority areas: 1) assessment of function and fatigability in older adults (NIA); 2) measurement of gait and posture biomechanics to monitor patients (NIAMS); 3) tools to enable mobile health and telemedicine by providing a means to monitor, evaluate, manage, track, train, and treat patients in underserved community settings and rural and remote locations (NIMHD, NINR); 4) tools for health informatics for clinical and translational research (NCATS); and 5) measurement of occupational health stressors in the workplace (NIOSH). For this Phase I STTR, Bioniks' goal is to provide therapists with an affordable and easy-to-use 3D movement analysis system that quantifies an athlete's risk for, or recovery from, lower extremity injury. Our first aim is to show that the movement analysis system will not only be accurate and reliable (Aim 1), but also be practical and easy to use (Aim 2). We hypothesize that: 1) our kinematic measurements will agree with those from a gold-standard laboratory-based motion capture system (Vicon); and 2) that therapists will judge our system to be more useful and usable than current clinical tools, including traditional 2D video analyses. To test these hypotheses, we will conduct a validation study with healthy volunteers at the UCSF Human Performance Center as well as a pilot usability study with therapists and healthy volunteers and patients with history of ACL injury at the SF Sports and Spine Physical Therapy Clinic.